YACReader: Fix crash when exiting while processing a comic

When quitting YACReader while processing a comic, the comic thread needs
to be properly terminated to avoid segfaults and other possible problems.

CHANGELOG.md

@@ -4,6 +4,8 @@ Version counting is based on semantic versioning (Major.Feature.Patch)
 
 ## WIP
 
+### YACReader
+*Fix segfault (or worse) when exiting YACReader while processing a comic
 ### YACReaderLibrary
 * Fixed drag&drop in the comics grid view.
 * Detect back/forward mouse buttons to move back and forward through the browsing history.

YACReader/render.cpp

@@ -382,20 +382,23 @@ Render::Render()
 
 Render::~Render()
 {
-    if (comic != nullptr) {
-        comic->moveToThread(QApplication::instance()->thread());
-        comic->deleteLater();
+    for (auto *pr : pageRenders) {
+        if (pr != nullptr && pr->wait()) {
+            delete pr;
+        }
     }
 
-    foreach (PageRender *pr, pageRenders)
-        if (pr != nullptr) {
-            if (pr->wait())
-                delete pr;
-        }
-
     // TODO move to share_ptr
-    foreach (ImageFilter *filter, filters)
+    for (auto *filter : filters) {
         delete filter;
+    }
+
+    if (comic != nullptr) {
+        comic->invalidate();
+        comic->deleteLater();
+        comic->thread()->quit();
+        comic->thread()->wait();
+    }
 }
 // Este método se encarga de forzar el renderizado de las páginas.
 // Actualiza el buffer según es necesario.

common/comic.cpp

@@ -890,8 +890,10 @@ void PDFComic::renderPage(int page)
 #endif
         QByteArray ba;
         QBuffer buf(&ba);
+        buf.open(QIODevice::WriteOnly);
         img.save(&buf, "jpg", 96);
         _pages[page] = ba;
+        buf.close();
         emit imageLoaded(page);
         emit imageLoaded(page, _pages[page]);
     }